The problem here is that we don't currently verify -l flags in .la files, only references from one .la to another. (Assuming there's only one problem, that is.)

First question that comes to mind: does the quoted example only require libgliz-glx.so with the same arch as /usr/lib64/libavahi-ui.so, or for every arch for which libavahi-ui.so exists? I think the former makes more sense, but I'm not sure exactly how libtool is supposed to interact with multilib.